Selective Detection of K+ by Ion-Selective Optode Nanoparticles on Cellulosic Filter Paper Substrates

Abstract

This work describes the generation of plasticized poly(vinyl chloride)-based ion-selective optode (ISO) nanoparticles by a piezoelectric inkjet dispensing device. The monodisperse inkjet-generated particles (polydispersity index: 0.177) with an average hydrodynamic diameter of 202 nm are suitable for the highly reproducible deposition onto cellulosic filter paper substrates, resulting in paper-based analytical devices (PADs) for colorimetric cation detection, as demonstrated on the example of potassium-responsive ISOs. In contrast to the deposition of ISO bulk membranes from organic solutions requiring specialized printing equipment, the ISO nanoparticles can be inkjet-deposited from aqueous dispersions by conventional office inkjet printing. The obtained ISO PADs showed highly reproducible (relative standard deviations of the hue mean values in the range of 0.06–0.83% for three independently fabricated batches) and immediate (t95% ≤ 1 min) response to aqueous K+ solutions buffered at pH 7.4, with high se...